Abstract Radish (Raphanus sativus), lettuce (Latuca sativa), and wheat (Triticum aestivum) plants were grown at either 98kPa (ambient) or 33kPa atmospheric pressure with constant 21kPa oxygen and 0.12kPa carbon dioxide in atmospherically closed pressure chambers. All plants were grown rockwool using recirculating hydroponics with a complete nutrient solution. At 20days after planting, chamber pressures were pumped down as rapidly as possible, reaching 5kPa after about 5min and ∼1.5kPa after about 10min. The plants were held at 1.5kPa for 30min and then pressures were restored to their original settings. Temperature (22°C) and humidity (65% RH) controls were engaged throughout the depressurization, although temperatures dropped to near 16°C for a brief period. CO2 and O2 were not detectable at the low pressure, suggesting that most of the 1.5kPa atmosphere consisted of water vapor. Following re-pressurization, plants were grown for another 7days at the original pressures and then harvested. The lettuce, radish, and wheat plants showed no visible effects from the rapid decompression, and there were no differences in fresh or dry mass when compared to control plants maintained continuously at 33 or 98kPa. But radish storage root fresh mass and lettuce head fresh and dry masses were less at 33kPa compared to 98kPa for both the controls and decompression treatment. The results suggest that plants are extremely resilient to rapid decompression, provided they do not freeze (from evaporative cooling) or desiccate. The water of the hydroponic system was below the boiling pressure during these tests and this may have protected the plants by preventing pressures from dropping below 1.5kPa and maintaining humidity near 1.5kPa. Further testing is needed to determine how long plants can withstand such low pressure, but the results suggest there are at least 30min to respond to catastrophic pressure losses in a plant production chamber that might be used for life support in space.
Plants survive rapid decompression: Implications for bioregenerative life support
Advances in Space Research ; 47 , 9 ; 1600-1607
2010-12-16
8 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Plants survive rapid decompression: Implications for bioregenerative life support
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